1. Bioenergy

What it is:Bioenergy can be produced using any sort of biological matter: lumber scraps, crops, human waste, etc. This biomass can be burned directly, heated and turned into natural gas or broken down chemically and turned into gas.

The pros: Bioenergy is highly renewable, technologically proven and it reduces waste. Technically, it’s also carbon-neutral, but that’s debatable—plants take carbon out of the air, but burning them just returns that carbon to the atmosphere.

The cons: Growing transportation costs also help make bioenergy more expensive than other types of renewables (and fossil fuels), so it’s not likely to reduce commercial electricity bills. And since most biofuels—like ethanol—are made from food like corn, many argue that those resources ought to go into feeding people, not making energy. Plowing, transportation and other factors in growing and moving these crops throw other pollutants into the air as well.

2. Geothermal

What it is:Geothermal energy harnesses the power of naturally hot water in the Earth. Steam from hot springs is used to spin turbines and create energy.

The pros: Geothermal is probably the cleanest type of energy, and it’s extremely reliable. It’s also completely renewable, as long as care is taken to preserve the hot water reservoir.

The cons: The biggest drawback to geothermal is that it’s very location-specific. Virtually all hot-water reservoirs are in the western United States, Alaska and Hawaii. While technological changes may soon make it cheaper, the initial investment in equipment is costly, and a lot of drilling and landscape changes may be needed. Geothermal also requires a lot of water, and—because it relies on a process similar to hydraulic fracking—it has become notorious for causing earthquakes.

3. Hydroelectric

What it is:About half of all renewable U.S. energy comes from hydroelectric, which harnesses the power of moving water. A typical hydroelectric generator uses a dam on a river or a creek. Pent-up water rushes through the dam’s turbines and produces electricity.

The pros: The electricity generated from hydroelectric energy can help reduce commercial utility bills. It also requires little maintenance, produces almost no pollution and is completely renewable. Droughts are the only major obstacle when it comes to reliability.

The cons: Unfortunately, dam building is expensive. Dams are also very location-specific. Building sites can be difficult to find. Just as importantly, hydroelectric can be a hard sell for corporate social responsibility, because dams harm wildlife in numerous ways—flooding land, altering geography and disrupting the movement of fish and wildlife.

4. Hydrogen

What it is:Hydrogen, a powerful form of commercial renewable energy, is extracted from water using electrolysis, which requires running electric current through water to extract hydrogen atoms.

The pros: Hydrogen fuel cells are clean, reliable and efficient. They’re typically used to power cars, generators and NASA spaceships.

The cons: There’s one big catch to hydrogen power: It takes a lot of energy—which often comes from fossil fuels—to pull hydrogen from water. That process is also really expensive. And there are other issues: Hydrogen has to be stored and transported under high pressure and is just as flammable as gasoline. Hydrogen may be the clean energy source of the future, but so far, using it is not the most sustainable business practice.

5. Ocean

What it is:Ocean power works like hydroelectric, but in a bigger body of water. Ocean waves spin turbine blades that create electricity.

The pros: Since two-thirds of our planet is covered by ocean, this kind of wave power makes sense as a commercial renewable energy. It doesn’t pollute, it’s efficient, it works round-the-clock and it’s as predictable as the tides.

The cons: Ocean-power technology is still relatively new, and there are many kinks to work out. Ocean energy is also one of the most expensive ways to generate electricity. The startup costs are high, and so are the maintenance costs, since ocean water is very corrosive to metal. In addition, the turbines can be harmful to wildlife, and these ocean power “farms” are often seen as an eyesore in beach communities.

6. Solar PV

What it is: Solar photovoltaic (PV)—not to be confused with solar thermal—is created when solar cells, or PV cells, convert sunlight directly into electricity.

The pros: Solar PV has a proven track record of reducing commercial electricity bills. The benefits of solar power for business include reliability, maintenance costs, ease of use, lack of noise and power that is much cheaper than fossil fuels over the 25-year (or longer) lifespan of a typical solar installation.

The cons: The two biggest knocks on solar are 1) it only works while the sun’s out, and 2) the startup price can be really high. The industry is working on both issues by introducing improved battery storage for the first and financing options for the second, but there are other considerations. Big power needs may require a big solar system, which in turn requires a lot of land. While offsite solar is an option for constrained space, giant solar farms have been tied to bird and bat deaths caused by heat or collision with panels. These deaths are fewer than those resulting from fossil-fuel generation, but environmentalists have still criticized some large solar projects.

7. Wind

What it is:Wind power (or wind energy) is exactly what it sounds like—the process by which wind is used to generate power. Turbines convert kinetic energy in the wind into electricity.

The pros: Wind power is often compared to solar PV as a sustainable business practice, as both have grown in the last few decades into mature industries that provide reliable power. Both have seen their efficiency soar, and continually-plummeting costs have made both extremely affordable.

The cons: Wind and solar have some of the same drawbacks. The startup cost for wind is high—obtaining the turbines is the biggest financial burden. Also, wind is tied to outdoor conditions. If the wind doesn’t blow, the turbines don’t spin. Wind power has also been linked to bird deaths because of the turbine blades, but (as with solar) these deaths are fewer than those caused by fossil-fuel generation. Of all the renewables, wind probably gets the biggest number of “not in my backyard” complaints. While some people love the sleek-looking turbines and think they’re quiet, others hate the sight of them and complain about the “whump-whumping” of the blades.

Here’s a summary chart so you can compare the pros and cons of each type of commercial renewable energy and determine which is right for your organization.

Bioenergy

Geothermal

Hydroelectric

Hydrogen

Ocean

Solar PV

Wind

Startup cost

Generally low

High

High

High

High

High

High

Cost of energy produced

High

Low

Low

High

Low

Low

Low

Maintenance

Varies

Moderate

Low

Low

High

Low

Moderate

Difficulty of use

Generally low, but can require sophisticated equipment

Moderate

Low

Moderate

Low

Low

Low

Reliability

High

High

High

High

High

High

High

Pollution

Depends on the biofuel used; some are high, others low

Low

Low

Low

Low

Low

Low

Harm to wildlife

Depends on the biofuel used; some are high, others low

Low

High

Low

Moderate

Low

Moderate

Noise

Generally low

High

Low

Low

Moderate

Low

Moderate

Not-in-my-backyard complaints

Moderate to high

Moderate

Moderate

Low

Moderate to high

Low to Moderate

Moderate to high

Limitations

Requires big storage areas for fuel

Location-specific; can't be done without geothermal springs nearby

Location-specific; can only be done at certain places on waterways

Very expensive and requires other types of energy to create

Location-specific; still new and largely undeveloped technology

Does not produce energy if the sun’s not out; space needed for solar arrays

Does not produce energy if the wind’s not blowing; space needed for turbines